In recent years, larger-scale semiconductor integrated circuits have been provided, for example, by utilizing complementary metal-oxide semiconductors (CMOS). This enables various internal circuits, for example, an analog signal processing circuit, a digital signal processing circuit, and a memory circuit, to be incorporated into a semiconductor integrated circuit. CMOSs have been miniaturized in order to promote an increase in the scale of semiconductor integrated circuits and improvement of the functions of semiconductor integrated circuits.
Miniaturized CMOSs have a reduced withstand voltage, precluding the internal circuits from utilizing a high driving voltage. The internal circuits currently have a specified voltage of, for example, 1.2 V. In this case, the internal circuits can operate normally when the driving voltage is about 1.0 V or higher and about 1.4 V or lower.